First knowledge of spring-summer demographic structure and reproductive characteristics of Mus spicilegus from Slovakia

Outdoor species Mus spicilegus Petenyi, 1882 were trapped in 2004–2006 on fields of eastern Slovakia in vicinity of village Kechnec (48°33′7.2′′ N, 21°14′25.0′′ E; 200 m a.s.l.). Spring-summer population demography and reproductive aspects (in period March – June) were analyzed in this study. Totally, 51 individuals of the outdoor mound-building mice were trapped. The sex ratio was in favor of males (χ2 = 1.96, df = 1, p > 0.05). Prevalence of adult mice was significantly higher than of subadults, and it was noticeable in males (χ2 = 9.75, df = 1, p < 0.01). For five pregnant females trapped during 2004–2006 average litter size was 8.6 (7–10) embryos per female. Evaluation of all pregnant females (n = 9) from Slovakia (2002–2006) confirmed similar values – 8.3 (6–10) embryos per female.